Revenge of a Yorkie- Bad Behavior

Question
If you could help me... Thank you in advance... I have an almost 2yr old yorkie named London,female,and she hasnt been spayed. She's different then most yorkies I've met, she's on the shy side. However, she's attached to my members of my household, which happens. I'm a member of 3 in my household. Whenever I leave the house I usually place her in the crate b/c I know if I leave her out she'll get into stuff. However, if my mom or sis leaves they may forget to put her in the crate. And when they come back London has gotten into their belongings. This has been going on for about a month & its getting worse. While we're all sleep at night, London usually sleeps in our rooms or in the bathroom, she'll rotate. However some nights we'll wake up to a bitten shoe or she'll get into our things. I just don't understand. She gets punished for it, but she keeps doing it. Oh, & I'm 7 months pregnant. My mother thinks she's possibly jealous. If you could help me out on why London is being so mischievous. Greatly appreciated.

Answer
There are a number of things going on.  Yes she knows you are pregnant and is behaving differently due to it.  Part of the solution is to be more careful to crate her when nobody is around.  Go ahead and get her spayed.  We already have far too many people breeding dogs.  It will make things better for everybody.  

The key to most behavior problems is approaching things using the dog's natural instincts.  Dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog.  Life is much easier if the 2 legged pack members outrank the 4 legged ones.  You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat. Start at http://www.dogsbestfriend.com/  For more on being top dog, see http://www.dogbreedinfo.com./topdogrules.htm